Wallboard trim construction



e. c. CABLE 3,255,561

WALLBOARD TRIM CONSTRUCTION June 14, 1966 Original Filed Aug. 6, 195630-- /20 I! 26 34 zz a0 10 GROVE C. CABLE,

INVENTOR.

A TTORNE K United States Patent 3,255,561 WALLEOARD TREM CONSTRUCTIONGrover C. Cable, Huntington Park, Califi, assignor to Angeles Metal TrimCo., Los'Angeles, Califi, a corporation of California Continuation ofabandoned application'Ser. No. 602,310,

Aug. 6, 1956. This application Feb. 23, 1960, Ser. No. 508

19 Claims. 0. 52255) This invention relates to improvements in buildingconstruction, and more particularly to an improved metal trim for use indry-wall type construction. This application is a continuation of myprior application, Serial Number 602,310, filed August 6, 1956, nowabandoned.

In applying dry-Wall construction to homes and other buildings, thewalls are formed by means of wallboard,

' such as gypsum rock panels, having cardboard or similar Where the edgeof sheets on the outer surfaces thereof. a piece of wallboard lies at acorner of a wall structure, whether it be the corner formed by theintersection of two wall surfaces or whether it be a corner formed alongthe edge of a door, window, or other opening, it is desirable to makesome provision for protecting and concealing the edge of the wallboard.Numerous types of metal trim members have been employed for thispurpose. In one type of trim member, the trim member is provided. with abead to form a rigid .edge at a corner formed. thereby, and a section ofthe trim member that is placed along the wall surface of the wallboardis provided with bonding holes and joint cement is applied over thattrim section in the reentrant portion of the trim member between thebead and beyond the edge of said trim section in order to conceal thetrim section and to form a mono lithic structure. Portions of the jointcement that enter the bonding holes are locked therein either by virtueof the cementitious bond formed between the joint cement and the portionof the wallboard opposite the bonding holes or because of enlargedportions of the joint cement that are formed on the inner side of thebonding holes, thereby forming key-locks with the trim section.

Heretofore the bonding holes that have been employed for this purposehave generally been circular in shape and have been located at positionsalong the length of the trim member that are spaced apart by distancessubstantially greater than the diameters of the bonding holes. Suchbonding holes have not proved entirely satisfactory,

and installations employing trim members with such bonding holes havebeen subject to serious fracture of the joint cement, thus detractingfrom the appearance of the wall. I

In order to form a smooth monolithic structure, it is very desirablethat the trim section be relatively thin and flat so that it can be laidflat against the wallboard or can form, in effect, an extension of theouter surface thereof. It is also desirable that the bead be small.

One of the objects of this invention is to provide an improved metaltrim member for protecting and concealing the edges of sections ofwallboard at various corners,

and which is provided with improved means for locking the joint cementin place.

Another object of the invention is to provide an improved trim member ofthe type described with bonding Patented June 14, 1966 "ice Theforegoing and other objects of this invention, together with variousadvantages thereof, will become apparent from the following descriptiontaken in connection With-the accompanying drawing, wherein:

FIGURE 1 is a cross-sectional viewof a corner of a wall embodying thepresent invention;

FIG. 2 is a perspective view of a section of corner-bead trim memberembodying the invention;

FIG. 3 is a cross-sectional view of a wall structure embodying anotherform of the invention; and

FIG. 4 is a perspective view of the metal trim member employed in thewall structure of FIG. 3.

Referring to the drawing, and particularly to FIG. 1, there isillustrated a wall corner to which an improved corner bead trim memberof the type illustrated in FIG. 2 has been applied. In this embodimentof the invention, a pair of pieces of wallboard 10 and 11 are laid onadjacent faces of a four-by-four or other structural member 12, therebyforming a pair of walls that lie at a right angle and that intersect at-a corner. Each piece of wallboard is generally formed by a core C ofgypsum rock material bonded tightly between two parallel sheets S ofcardboard or other cover material.

Sometimes the edge 13 of one of the piecesof wallboard lies in the planeof the outer edge of the other piece of wallboard, and the end 15 of theother piece of wallboard 10 abuts the adjacent end of the other piece ofwallboard 11, forming a clearly defined right-angle corner. Other times,however, a good fit is not provided, especially where, as in the exampleillustrated in FIG. 1, the edge of a piece of wallboard has been brokenaway, thus leaving a cavity 16 between the edge of the piece ofwallboard 10 and the other piece of wallboard 11, or even leaving avacant space 18 at a corner formed by the two pieces of wallboard.

To complete and finish and strength the corner, a strip of corner-beadmetal trim 20, as illustrated in FIG. 1, is laid along the corner. Themetal trim member 20 is of unitary construction and is formed from anelongated strip of metal which is shaped to provide a pair of straightsubstantially planar trim sections 22 and 24. joined together by-meansof a convex bead 26. The two side sections 22 and 24 are substantiallyflat, andeach of them is of elongated rectangular configuration. Thebead 26 may be of a number of dilterent shapes, and in particular mayhave a circular arcuate cross-sectional configuration.

The two trim sections 22 and 24 are inclined to each other and aregenerally substantially orthogonal to each other in the best embodimentsof the invention. Each of the trim sections 22 and 24 is provided with arow of nail holes 30 along the outer edge thereof remote from the bead26. Each of the trim sections is also provided with at least two rows ofbonding holes. The holes in at least one row are in the form ofelongated slots. But, in the best embodiment of the invention, two rowsof bonding slots are employed, in each of the trim sections 22 and 24 asillustrated in FIG. 2.

One row of elongated slots 32 is arranged along a line more nearlyadjacent the row of nail holes 30,. The other row of elongated slots 34is arranged along a line nearer to the bead 26. For reasons which willbecome apparent hereinafter, theinner slots 34 are longer than the outerslots 32, and they are narrower than the outer slots. In the bestembodiment of the invention, the slots extend lengthwise of the trimmember and substantially parallel to the head 26. The lengths of theslots are.

made less than about the widths of the trim sections 22 and 24 and theWidths of the slots are much smaller than the widths of the trimsections so that the slots do not make the trim member so flexible orflimsy that the trim member cannot be easily handled and applied asdescribed hereinafter. Such retention of rigidity is enhanced byarranging the slots substantially parallel to the length of the trimmember.

In the form of the invention illustrated in FIGS. 1 and 2, the lengthsof the slots 32 and 34 are such that adjacent slots in the two rows donot overlap. However, only very small lengthwise sections of each trimsection are free of slots. In other words, the projections of the slots32 and 34 onto a base line along the length of the trim member, such asthe outer edge of either trim section 22 or 24, do not overlap. A fourthrow of holes 36 is formed in each trim section 22 and 24 along a lineadjacent the head 26 and between the bead 26 and the nearest row ofslots 34. The centers of the bonding holes 36 are located opposite theouter slots 32, while the nail holes 30 are located opposite the innerslots 34. Knurling 38 is formed on the surface of each trim section 22and 24, thus rendering both surfaces of each trim section slightlyirregular.

In one specific embodiment of the invention as applied to the cornerbead that has been found to be very satisfactory in practice, the cornerhead was made of 26-gauge bonderized stell strip forming a corner beadhaving an external diameter of about Ms and having trim sections havingwidths of about The outer slots 32 had lengths of W and widths of 1/ Theinner slots 34 had lengths of and widths of The nail holes 30 and thebonding holes 36 were of the same size and had diameters of A3". Thecenters of the holes in each row were spaced 1 /2" apart. Furthermore,the holes 30, 32, 34, an d 36 were located 7 and respectively from theouter edge of the trim section in which they were formed. Such trimmembers are manufactured in standard lengths of, say, 8 feet.

To apply the trim member 20 of FIG. 2 to a corner, as illustrated inFIG. 1, a trim member of suitable length is placed at the corner withthe two trim sections 22 and 24 disposed along the outer surfaces of thetwo pieces of wallboard 10 and 11. Suitable fastener elements, such asnails 40, driven through alternate nail holes 30 and through theadjacent pieces of wallboard into the Wood structural member 12 assure arigid mounting of the trim member 20 in place. When so mounted, the trimsections 22 and 24 constitute, in effect, extensions of the outersurfaces of the pieces of wallboard 10 and 11 to a rigid round cornerformed by the bead 26. When so mounted, a reentrant portion is providedalong each trim section 22 and 24 between the bead 26 and the outer edgeof the trim section.

To finish the installation, a body of filler material, or joint cement,is applied over each trim section, filling each of the reentrantportions and covering the outer edges of the trim sections and theadjacent parts of the Wallboard. Preferably three coats of such a fillermaterial are applied in such a way as to form a flat, gradually taperedbody of filler material that covers and conceals the trim sections 22and 24 and the adjacent portions of the pieces of wallboard. In applyingthe joint cement, it is squeezed into and through the bonding slots 32and 34 and the bonding holes 36. V

In locations where the slots 34 and holes 36 are disposed close to theexternal paper coatings on the outer surfaces of the pieces of wallboard10 and 11, the joint cement adheres directly to the paper. In otherlocations, such as where cavities or other recesses 16 and 18 areformed, joint cement passes through the slots 34, bulging outwardly andforming key-locks. In some cases, the knurling produces slight gapsbetween the trim sections 22 and 24 and the wallboard, thus permittingsome joint cement to seep behind the trim sections 22 and 24 and thusaid in locking the joint cement in place. Similarly, joint cemententering or passing through the bonding holes 36 either becomes adheredto the gypsum rock composition forming the core C of the adjacent pieceof wallboard or forms a key-lock. Inasmuch as cavities 16 are morelikely to be located adjacent the inner slots 34, best results areobtained by making these slots long and narrow, since this reduces theamount of joint cement likely to be squeezed through the slots 34.

By smoothing the outer surface of the filler material, it is readilyfeathered at the points where it covers the Wallboard, and it isrendered flush with the outer edge of the bead 26. The entire surface ofthe wall is then painted, thus forming a fiat smooth monolithicstructure.

By employing bonding holes in the form of slots, as described above,portions of the joint cement are firmly secured to the trim memberthroughout its entire length. With this type of structure, the jointcement is secured more firmly in place, and the joint cement istherefore less liable to fracture or to be chipped off or to stripbecause of impacts on the bead or otherwise.

In FIG. 3, another embodiment of the invention is illustrated employinga channel-shaped trim member of the type illustrated in FIG. 4. Thisspecific type of trim member, except for the bonding arrangement, is thesame as that disclosed and described in Patent No. 2,725,608 issued toAngeles Metal Trim Co. on the basis of an application by Thomas W.Parslow. In this case, however, the trim member is U-shaped, beingprovided with a front trim section 52, a side trim section 54, and arear trim section 56. The rear edge of the side section 54 is joined tothe rear section 56 by a rear bead 57, and the front edge of the sidesection 54 is joined to the front section by a bead 53, all as describedin more detail in said patent. The side trim section is plane and freeof holes so as to provide a smooth finished surface. In this case, nailholes 30 and bonding holes 32, 34, and 36 are arranged as describedabove in the front section 52 only. In this particular case, however,the projections of the bonding holes 32 and 34 in the different rowsonto a line extending lengthwise of the metal trim member 50 may overlapslightly as shown in FIG. 4, or not at all as seen in FIG. 2. Both inthis case and in that described above, the projections of the bondingholes onto such a line occupy at least substantially all of that line.

The metal trim member 50 is mounted in place with the rear bead 57pressed against the outer exposed surface of a structural member 60,such as a jarnb surrounding an opening 62 for a door 64, and the trimmember is secured firmly in place by means of nails 66 driven throughnail holes 30 and through a piece of wallboard 68 into anotherstructural member, such as a cripple 70. As in the case described above,joint cement is disposed in the reentrant portion formed by the fronthead 53 and the front section 52, becoming securely locked in place andcovering and concealing the front section 52, the heads of the nails 66,and the adjacent portion of the wallboard 68.

While the invention has been described with particular reference to aspecific embodiment thereof, it will now be obvious to those skilled inthe art that many changes may be made in the shape and dimensions of theparts and in the material from which the trim member is made Withoutdeparting from the invention. More particularly, it will be understoodthat changes may be made in the size and shape of the slots and theother holes without departing from the principles of the invention.Furthermore, even though the invention has been described only withreference to its application to trim members that have two trim sectionsthat are arranged orthogonally with respect to each other, the inventionmay be applied to trim members in which the trim sections are arrangedat some other angle, and that the invention may be applied to othertypes of trim members as well. It is therefore to be understood that theinvention is not limited to the specific embodiments thereof that havebeen described in detail herein, but includes other embodiments within 7the scope of the appended claims.

The invention claimed is: 1. In combination with a structural member ofa building and a substantially fiat piece of wallboard overlying saidstructural member:

an elongated unitary trim member substantially rigid, both transverselyand longitudinally and comprising a pair of straight substantiallyplanar trim sections and having an elongated convex bead joining saidtrim sections along a common junction edge extending lengthwise of saidtrim member, said trim sections being inclined to each other, said trimmember being disposed over an edge of said piece of wallboard, one ofsaid trim sections being disposed upon the outer face of said piece ofwallboard and the other of said trim sections extending in a directionto cover and protect said edge of said piece of wallboard whereby saidbead forms a rigid corner and provides a reentrant portion along onetrim section, said trim member and wallboard further defining a cavityadjacent the interior of said trim member and between said structuralmember and said edge of said wallboard;

a plurality of fasteners extending through said one trim section andthence through said piece of wallboard into said structural member;

said one trim section having at least two substantially parallel rows ofopenings formed therein between said bead and the edge of said onetrimsection remote from said bead, the openings in at least one of saidrows being in the form of elongated slots that extend lengthwise of saidtrim member and overlie said wallboard, the openings in the other ofsaid rows including openings having a lesser open area than that of anyof said elongated slots and disposed to overlie said cavity;

and a body of filler material adjacent said one trim section and fillingthe reentrant portion thereof, the outer surface of said filler materialbeing flush with the outer edge of said elongated bead, said body offiller material covering the ege of said one trim section remote fromsaid bead, whereby the edge of said one trim section and the adjacentportion of said wallboard are concealed, portions of said body of fillermaterial extending in different amounts through said differently sizedopenings and being locked therein.

2. In combination with a structural member of a building and asubstantially flat piece of wallboard overlying said structural member,said piece of wallboard defining a cavity between a portion thereof andsaid structural member:

an elongated unitary trim member substantially rigid, both transverselyand longitudinally and comprising a pair of straight substantiallyplanar trim sections and having an elongated convex bead joining saidtrim sections along a common junction edge extending lengthwise of saidtrim member, said trim sections being inclined to each other, said trimmember being disposed over an edge of said piece of wallboard inoverlying relation to a surface of said wallboard, as well as inoverlying relation to said cavity, one of said trim sections beingdisposed upon the outer face of said piece of wallboard and the other ofsaid trim sections extending in a direction to cover and protect saidedge of said piece of wallboard whereby said bead forms a rigid cornerclosing said cavity and a portion of said wallboard and provides areentrant portion along said one trim section;

a plurality of fasteners extending through said one trim section andthence through said piece of wallboard into said structural member;

said one trim section having at least two substantially parallel rows ofelongated slots formed therein between said bead and the edge of saidone trim section remote from said bead, said slots extending lengthwiseof said trim member, the projections of said slots onto a base linealong the length of said trim memher occupying substantially all of saidline without substantial overlapping, some of said slots overlying thesurface of said wallboard and others of said slots overlying saidcavity, said other slots being narrower than said first-mentioned slots;

and a body of filler material adjacent said one trim section and fillingthe reentrant portion thereof, the

outer surface of said filler material being fiush with the outer edge ofsaid elongated bead, said body of filler material covering the edge ofsaid one .trim

section remote from said bead, whereby the edge of said one trim sectionand the adjacent portion of said wallboard are concealed, portions ofsaid body of filler material extending through said slots and beinglocked therein. I

3. In the combination specified in claim 2, an elongated trim member inwhich the lengths of said slots are less than about the width of saidone trim section.

4. In the combination specified in claim 2, an elongated trim member inwhich the widths of said slots are small compared with the width of saidone trim section.

5. In the combination specified in claim 2, an elongated trim member inwhich the lengths of said slots are less than about the width of saidone trim section and the widths of said slots are small compared withthe width of said one trim section.

6. The combination specified in claim 2, wherein said elongated trimmember has an auxiliary row of bonding holes located between said rowsof slots and said head, said bonding holes being positioned opposite thespaces between successive slots of the row of slots that is nearest saidhead.

7. A combination as in claim 2 wherein slots in one of said parallelrows are longer than the slots in the other of said parallel rows andthe longer slots are narrower than the shorter slots.

8. In combination with a structural member of a building and asubstantially fiat piece of wallboard overlying said structural member:1

an elongated unitary trim member substantially rigid,

both transversely and longitudinally and comprising a pair of straightsubstantially planar trim sections and having an elongated convex beadjoining said trim sections along a common junction edge extendinglengthwise of said trim member, said trim sections being arrangedsubstantially orthogonal with respect to each other, said trim memberbeing disposed over an edge of said piece of wallboard, one of said trimsections being disposed upon the outer face of said piece of wallboardand the other of said trim sections extending in a directionsubstantially normal to said outer face and in a direction to cover andprotect said edge of said piece of wallboard whereby said bead forms arigid corner and provides a reentrant portion along said one trimsection;

means for fastening said unitary trim member to said piece of wallboard;

said one trim section having at least two substantially parallel rows ofdifferently dimensioned elongated slots formed therein between said beadand the edge of said one trim section remote from said bead, said slotsextending lengthwise of said trim member, the projections of said slotsonto a base line along the length of said trim member occupyingsubstantially all of said line without substantial overlapping;

and a body of filler material adjacent said one trim section and fillingthe reentrant portion thereof, the outer surface of said filler materialbeing flush with the outer edge of said elongated bead, said body offiller material covering the edge of said one trim section remote fromsaid bead, whereby the edge of said one trim section and the adjacentportion of said wallboard are concealed, portions of said body of fillermaterial extending in different amounts,

through said differently dimensioned elongated slots and being lockedtherein. 9. In combination with a structural member of a building and apair of substantially flat pieces of wallboard overlying adjacent partsof said structural member and forming a corner adjacent said structuralmember:

an elongated unitary trim member substantially rigid, both transverselyand longitudinally and comprising a pair of straight substantiallyplanar trim sections and having an elongated convex bead joining saidtrim sections along a common junction edge extending lengthwise of saidtrim member, said trim sections being inclined to each other, said trimmember being disposed upon the respective pieces of wallboard in aposition to cover and protect the edges of said pieces of wallboardadjacent said structural member, whereby said bead forms a rigid corneradjacent said first-mentioned corner and provides reentrant portionsalong said trim sections;

fastening means extending from each of said trim sections for fasteningsaid pair of trim sections to said pair of pieces of wallboardrespectively;

each said trim section having at least two substantially parallel rowsof openings formed therein between said bead and the edge of each saidtrim section remote from said bead, the openings in at least one of saidrows of each trim section being in the form of slots extendinglengthwise of said trim member, the projections of said openings of eachsaid trim section onto a base line extending along the length of saidtrim member occupying substantially all of said line without substantialoverlapping;

and a body of filler material disposed on each said trim section andfilling the corresponding reentrant portion of said trim member, theouter surface of said filler material being fiush withsthe outer edge ofsaid elongated bead, said bodies of filler material covering the edgesof said trim sections remote from said bead, whereby each of said trimsections and the adjacent portions of said wallboard are concealed,portions of said bodies of filler material extending through saidopenings and being locked therein.

10. In combination with a structural member of a building and a pair ofsubstantially flat pieces of wallboard overlying adjacent parts of saidstructural member and being at right angles to each other, therebyforming a corner adjacent said structural member:

an elongated unitary trim member substantially rigid,

both transversely and longitudinally and comprising a pair of straightsubstantially planar trim sections and having an elongated convex beadjoining said trim sections along a common junction edge extendinglengthwise of said trim member, said trim sections being orthogonal toeach other, said trim member being disposed upon the respective piecesof wallboard in a position to cover and protect the edges of said piecesof wallboard adjacent said structural member, whereby said bead forms arigid corner adjacent said first-mentioned corner and provides reentrantportions along said trim sections;

each said trim section having at least two substantially parallel rowsof elongated slots formed therein between said bead and the edge of eachsaid trim section remote from said bead, said slots extending lengthwiseof said trim member and the elongated slots in one of said rows beingdisposed in staggered relation to the elongated slots in the other ofsaid rows, the projections of said slots of each said trim section ontoa base line along the length of said trim member occupying substantiallyall of said line without substantial overlapping;

and a body of filler material disposed on each said trim section andfilling the reentrant portion thereof, the outer surface of said fillermaterial being flush with the outer edge of said elongated bead, saidbodies of filler material covering the edges of said trim sectionsremote from said head, whereby each of said trim sections and theadjacent portions of said wallboard are concealed, portions of saidbodies of filler material extending through said slots and being lockedtherein.

11. An elongated unitary trim member which is substantially rigid bothlongitudinally and transversely, said trim member having a pair ofstraight substantially planar trim sections and having an elongatedconvex bead joining said trim sections along a common junction edgeextending lengthwise of said trim member, said trim sections beingarranged at an angle to each other for disposition around a corner of abuilding structure, whereby said bead will form a rigid corner at thecorner of such building structure, said head providing reentrantportions along said trim sections, each of said trim sections having atleast two substantially parallel rows of elongated slots extendinglengthwise of said trim section, the projections of said slots on eachtrim section onto a base line, which extends the length of said trimmember, occupying substantially all of said base line withoutsubstantial overlapping, said rows of slots being laterally spaced oneach trim section, and the slots of each row being longitudinally spacedalong the trim section, whereby to retain substantial rigidity of thetrim member both longitudinally and transversely, said slots beingadapted to serve as bonding openings to receive filler material appliedin said reentrant portions to lock such filler material in place.

12. An elongated rigid trim member as in claim 11 wherein at least someof the elongated slots in parallel rows closer to said bead are narrowerthan the elongated slots in parallel rows more remote from said head,thereby to permit a lesser amount of said filler material to passthrough said narrower slots than through said more remote slots.

13. A trim member as in claim 12 wherein said narrower slots in theparallel rows are longer than said other slots.

14. A trim member as in claim 11 wherein slots closer to said head arelonger than other slots and the longer. slots are narrower than theshorter slots.

15. A trim member as in claim 11 wherein said trim sections have nailholes arranged in a row out of vertical alignment with said slots anddisposed in transverse alignment with portions of respective slotstransversely remote from the respective nail holes.

16. A trim member as in claim 15 wherein said nail holes are locatedalong the outer edges of said trim sections and an auxiliary row ofbonding holes is located between said slots and said bead and oppositethe spaces between the slots of the nearest row of slots, and each ofsaid bonding holes has an open area less than that of any of said slots.

17. In combination with a structural member of a building:

a pair of substantially fiat pieces of wall-board overlying adjacentparts of said structural member and being disposed at right angles toeach other, the edge portion of one of said wallboard pieces overhangingthe adjacent edge of the other of said wallboard pieces and providing asubstantially filled longitudinally extending corner adjacent saidstructural memiber;

an elongated trim member which is substantially rigid, bothlongitudinally and transversely, and includes a pair of straightsubstantially planar trim sections disposed substantially at rightangles to each other and having an elongated convex bead joining saidtrim sections along a common junction edge extending lengthwise of saidtrim member, said trim sections being disposed upon the respectivepieces of wallboard in a position to cover and protect said cornerprovided by the edge portions of said wallboard pieces, whereby saidbead forms a rigid corner and provides re-entrant portions along saidtrim sections, each of said trim sections having at least twosubstantially parallel rows of differently dimensional elongated slotsformed therein between said bead and the outer edge of the respectivetrim section,

said slots extending lengthwise of said trim member, and the projectionsof said slots of each trim section onto a base line extending the lengthof the trim member occupying substantially all of said line withoutsubstantially overlapping.

'18. A combination as in claim 17 wherein some of the slots of theparallel rows of slots of each trim section are longer than other slotsand the longer slots are narrower than the shorter slots.

19. A combination as in claim 17 wherein a body of filler material isdisposed on each of said trim sections and fills the reentrant portionthereof, portions of said References Cited by the Examiner UNITED STATESPATENTS 1,308,773 7/1919 Clark 52-255 1,308,889 7/1919 Clark 52-2551,804,564. 5/1931 'McChesney 52-255 FRANK L. ABBOTT, Primary Examiner.

WILLIAM I. MUSHAKE, Examiner.

T. W. FLYNN, Assistant Examiner.

1. IN COMBINATION WITH A STRUCTURAL MEMBER OF A BUILDING AND ASUBSTANTIALLY FLAT PIECE OF WALLBOARD OVERLYING SAID STRUCTURAL MEMBER:AN ELONGATED UNITARY TRIM MEMBER SUBSTANTIALLY RIGID, BOTH TRANSVERSELYAND LONGITUDINALLY AND COMPRISING A PAIR OF STRAIGHT SUBSTANTIALLYPLANAR TRIM SECTIONS AND HAVING AN ELONGATED CONVEX BEAD JOINING SAIDTRIM SECTIONS ALONG A COMMON JUNCTION EDGE EXTENDING LENGTHWISE OF SAIDTRIM MEMBER, SAID TRIM SECTIONS BEING INCLINED TO EACH OTHER, SAID TRIMMEMBER BEING DISPOSED OVER AN EDGE OF SAID PIECE OF WALLBOARD, ONE OFSAID TRIM SECTIONS BEING DISPOSED UPON THE OUTER FACE OF SAID PIECE OFWALLBOARD AND THE OTHER OF SAID TRIM SECTIONS EXTENDING IN A DIRECTIONTO COVER AND PROTECT SAID EDGE OF SAID PIECE OF WALLBOARD WHEREBY SAIDBEAD FORMS A RIGID CORNER AND PROVIDES A REENTRANT PORTION ALONG ONETRIM SECTION, SAID TRIM MEMBER AND WALLBOARD FURTHER DEFINING A CAVITYADJACENT THE INTERIOR OF SAID TRIM MEMBER AND BETWEEN SAID STRUCTURALMEMBER AND SAID EDGE OF SAID WALLBOARD; A PLURALITY OF FASTENERSEXTENDING THROUGH SAID ONE TRIM SECTION AND THENCE THROUGH SAID PIECE OFWALL BOARD INTO SAID STRUCTURAL MEMBER; SAID ONE TRIM SECTION HAVING ATLEAST TWO SUBSTANTIALLY PARALLEL ROWS OF OPENINGS FORMED THEREIN BETWEENSAID BEAD AND THE EDGE OF SAID ONE TRIM SECTION REMOTE FROM SAID BEAD,THE OPENINGS IN AT LEAST ONE OF SAID ROWS BEING IN TEH FORM OF ELONGATEDSLOTS THAT EXTEND LENGTHWISE OF SAID TRIM MEMBER AND OVERLIE SAIDWALLBOARD, THE OPENINGS IN TEH OTHER OF SAID ROWS INCLUDING OPENINGSHAVING A LESSER OPEN AREA THAN THAT OF ANY OF SAID ELONGATED SLOTS ANDDISPOSED TO OVERLIE SAID CAVITY; AND A BODY OF FILLER MATERIAL ADJACENTSAID ONE TRIM SECTION AND FILLING THE REENTRANT PORTION THEREOF, THEOUTER SURFACE OF SAID FILLER MATERIAL BEING FLUSH WITH THE OUTER EDGE OFSAID ELONGATED BEAD, SAID BODY OF FILLER MATERIAL COVERING THE EGE OFSAID ONE TRIM SECTION REMOTE FROM SAID BEAD, WHEREBY THE EDGE OF SAIDONE TRIM SECTION AND THE ADJAENT PORTION OF SAID WALLBOARD ARECONCEALED, PORTIONS OF SAID BODY OF FILLER MATERIAL EXTENDING INDIFFERNT AMOUNTS THROUGH SAID DIFFERNTLY SIZED OPENINGS AND BEING LOCKEDTHEREIN.